Hwo do you reconcile the following two statements by you:
still file not gets uploaded.It should be in the same dir as cgi script.
default directory is current directory of cgi script +"/files".
I highly recommend reading jQuery::File::Upload and finding out where the error logs for your webserver are stored and getting access to them.
Maybe you also want to make sure that the default upload directory does exist and the user the web server is running as, and/or the user your script is running as are allowed to create files in that directory.